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The combustion of diesel fuels injected into a bomb at 25 bar and 520°C has been modelled and studied experimentally using laser diagnostics. A CFD model of diesel spray injection was combined with a database of results from a detailed chemical kinetic model. All fuels showed the presence of small aromatics throughout combustion (i.e. the fuel aromatics were not completely broken down). The model gave good agreement on spray penetrations and soot volume fractions around the edges of the spray. Far from the spray, the model over-predicted the amount of soot due to the absence of an OH oxidation mechanism in the CFD code. This demonstrates the need to progress to the use of a reduced chemistry scheme.

A critical concern for ASTOVL aircraft during landing manoeuvres is the deterioration in engine stability margin and performance due to the ingestion of hot gas from the engine exhaust into the engine inlets. This paper describes a methodology for the quantitative accounting of the effect of Hot Gas Ingestion (HGI) on engine stability and performance. To maximise performance and minimise design risk it is essential to have a technology data base to assess the likely HGI characteristics of candidate ASTOVL configurations and to identify measures to minimise HGI. This paper assesses the aircraft design features required to obtain low HGI characteristics for a wide range of ASTOVL configurations. Studies of steady-state CFD methods have commenced to determine their ability to model HGI flow paths of alternative aircraft configurations.